<template>
  <div id="home">
    <nav-bar class="home-nav">
      <div slot="center">购物车</div>
    </nav-bar>
    <tab-control :titles="['流行', '新款', '精选']"
                 @tabClick="tabClick" ref="tabControl1"
                 class="tab-control" v-show="isTabFixed" />
    <scroll class="content"
            ref="scroll"
            :probe-type="3"
            @scroll="contentScroll"
            :pull-up-load="true"
            @pullingUp="loadMore"
    >
      <home-swiper :banner="banner" @swiperImageLoad="swiperImageLoad" />
      <recommend-view :recommend="recommend" />
      <feature-view />
      <tab-control :titles="['流行', '新款', '精选']"
                   @tabClick="tabClick" ref="tabControl2" />
      <goods-list :goods="showGoods" />
    </scroll>
<!--    <back-top @backClick="backClick" />-->
    <back-top @click.native="backClick" v-show="isShowBackTop" />
  </div>
</template>

<script>
  import NavBar from 'components/common/navbar/NavBar'
  import TabControl from "components/content/tabControl/TabControl"
  import GoodsList from "components/content/goods/GoodsList"
  import Scroll from 'components/common/scroll/Scroll'
  import BackTop from 'components/content/backTop/BackTop'

  import HomeSwiper from "./childComps/HomeSwiper"
  import RecommendView from "./childComps/RecommendView"
  import FeatureView from "./childComps/FeatureView"

  import { getHomeMultidata, getHomeGoods } from 'network/home'
  // import { debounce } from "common/utils"
  import { itemListenerMixin } from 'common/mixin'
  import { BACKTOP_DISTANCE } from 'common/const'

  export default {
    name: "Home",
    components: {
      NavBar,
      TabControl,
      GoodsList,
      Scroll,
      BackTop,
      HomeSwiper,
      RecommendView,
      FeatureView
    },
    mixins: [itemListenerMixin],
    data() {
      return {
        // result: null,
        banner: [],
        recommend: [],
        goods: {
          'pop': {page: 0, list: []},
          'new': {page: 0, list: []},
          'sell': {page: 0, list: []}
        },
        currentType: 'pop',
        isShowBackTop: false,
        tabOffsetTop: 0,
        isTabFixed: false,
        saveY: 0,
        // itemImgListener: null
      }
    },
    computed: {
      showGoods() {
        return this.goods[this.currentType].list
      }
    },
    destroyed() {
      console.log('home destroyed');
    },
    activated() {
      this.$refs.scroll.scrollTo(0, this.saveY, 0)
      this.$refs.scroll.refresh()
    },
    deactivated() {
      // 1.保存Y值
      this.saveY = this.$refs.scroll.getScrollY()
      // console.log(this.saveY)
      // 2.取消全局事件的监听
      this.$bus.$off('itemImageLoad', this.itemImgListener)
    },
    created() {
      // 1.请求多个数据
      this.getHomeMultidata()
      // 2.请求商品数据
      this.getHomeGoods('pop')
      this.getHomeGoods('new')
      this.getHomeGoods('sell')
    },
    mounted() {
      // 1.监听item中图片加载完成
      // const refresh = debounce(this.$refs.scroll.refresh, 50)
      // 对监听的事件进行保存
      // this.itemImgListener = () => {
      //   // console.log('------')
      //   // this.$refs.scroll.refresh()
      //   refresh()
      // }
      // this.$bus.$on('itemImageLoad', this.itemImgListener)
    },
    methods: {
      /**
       * 事件监听相关的方法
       */
      tabClick(index) {
        // console.log(index)
        switch(index) {
          case 0:
            this.currentType = 'pop'
            break
          case 1:
            this.currentType = 'new'
            break
          case 2:
            this.currentType = 'sell'
            break
        }
        this.$refs.tabControl1.currentIndex = index
        this.$refs.tabControl2.currentIndex = index
      },
      backClick() {
        // console.log('backClick')
        this.$refs.scroll.scrollTo(0, 0)
      },
      contentScroll(position) {
        // 1.判断BackTop是否显示
        this.isShowBackTop = (-position.y) > BACKTOP_DISTANCE
        // 2.决定tabControl是否吸顶（position: fixed）
        this.isTabFixed = (-position.y) > this.tabOffsetTop
      },
      loadMore() {
        // console.log('加载更多');
        this.getHomeGoods(this.currentType)
      },
      swiperImageLoad() {
        // 2.获取tabControl的offsetTop
        // 所有的组件都有一个属性$el:用于获取组件中的元素
        this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop
        console.log(this.$refs.tabControl2.$el.offsetTop)
      },
      /**
       * 网络请求相关方法
       */
      getHomeMultidata() {
        getHomeMultidata().then(res => {
          // console.log(res)
          // this.result = res.data
          this.banner = res.data.banner.list
          this.recommend = res.data.recommend.list
        })
      },
      getHomeGoods(type) {
        const page = this.goods[type].page + 1
        getHomeGoods(type, page).then(res => {
          // console.log(res)
          this.goods[type].list.push(...res.data.list)
          this.goods[type].page += 1
          //完成上拉加载更多
          this.$refs.scroll.finishPullUp()
        })
      }
    }
  }
</script>

<style scoped>
  #home {
    /*padding-top: 44px;*/
    height: 100vh;
  }
  .home-nav {
    background-color: var(--color-tint);
    color: #fff;
    /*在使用浏览器原生滚动时，为了让导航不跟随一起滚动*/
    /*position: fixed;*/
    /*left: 0;*/
    /*right: 0;*/
    /*top: 0;*/
    /*z-index: 9;*/
  }
  /*.tab-control {*/
  /*  position: sticky;*/
  /*  top: 44px;*/
  /*  z-index: 9;*/
  /*}*/
  .content {
    overflow: hidden;
    position: absolute;
    top: 44px;
    bottom: 49px;
    left: 0;
    right: 0;
  }
  .tab-control {
    position: relative;
    z-index: 9;
  }
  /*.content {*/
  /*  height: calc(100% - 93px);*/
  /*  overflow: hidden;*/
  /*  margin-top: 51px;*/
  /*}*/
</style>
